Text on a curve with consistent length
Maybe what you are looking for are Monospaced Fonts

Monospace fonts are often used in programming, code editors and command line environments and use the same space between characters regardless of the glyph width.

Just pick any monospaced font file for use in a Blender text object and it should solve this particular case.



If you don't have one you can freely download any from the internet.

If all strings will have the same length then it would solve your problem, otherwise you would have to find a way to adjust character spacing on a case by case basis.